During the closure, SEPTA's in-house engineering, maintenance and construction crews will work around-the-clock on key maintenance and construction tasks to improve service reliability. The major portion of this work entails replacing approximately 10,000 feet of worn overhead wire and 2,500 feet of ceiling trough.

"We use the tunnel almost 24 hours a day, which means we have very limited opportunities to obtain track outages for extensive repair work," said SEPTA Deputy General Manager Jeff Knueppel. "We are taking advantage of this time to complete several projects that will improve our trolley service through the tunnel."

Other work that will be completed during the trolley closure includes replacing worn track components and completing regular track maintenance throughout the tunnel; replacing worn components on key track switches near 34th Street and conducting routine maintenance and performing maintenance tasks at stations and key stairways.